Malignancies, osseous

The Wilms tumor-1 (WTl) gene is located on the short arm of chromosome 11 (llpl3). It encodes a protein that is a critical determinant of urogenital development and is expressed in >80% of nephroblastomas. With regard to osseous and soft tissue tumors, WTl protein is not a specific marker and is potentially present in angiosarcoma, malignant peripheral nerve sheath tumor, synovial sarcoma, osteosarcoma, myxoid liposarcoma, and clear-cell sarcoma.Nevertheless, it is most often utilized (in a structured panel with other immunodeter-minants) as an adjunctive indicator of endothelial differentiation in diagnostic practice. ... 

One of the greatest challenges in the realm of bone and soft tissue tumor pathology is the reliable recognition of osseous matrix production in malignant... 

Yousem SA, Hochholzer L. Malignant mesotheliomas with osseous and cartilaginous differentiation. Arch Pathol Lab Invest. 1987 111 62-66. 

A subset of patients with hypercalcaemia related to a malignancy show no evidence of excess parathyroid hormone production or osseous metastases. PG have been implicated in the pathogenesis of malignancy-related hypercalcaemia, since PG enhance bone resorption, and are necessary for the synthesis of osteoclastic activating factor. Some patients with renal cell carcinoma and concomitant hypercalcaemia have been shown to have elevated renal PG levels which can be suppressed with indomethacin. 

Bone marrow malignancies are primarily subject for MR diagnostics, since MRI can directly display the bone marrow components. The role for MDCT is on the one hand to show the matrix of a bone tumor and on the other hand to evaluate the extension of osseous destructions and to assess the fracture risk. More and more whole-body exams are performed in patients with multifocal metastases or multiple myeloma. 

Fig. 35.6. Coronal reconstruction of a MDCT dataset in an 81 -year-old female with a large enchondroma of the femur. Typical popcorn-like calcifications within the marrow cavity, no osseous destructions or periosteal reactions indicative of malignancy are visualized. The diagnosis of a benign enchondroma was proven by biopsy...

In contrast, secondary osseous malignancies may occur in about 30%-70% of all malignant diseases. For example, in breast and prostate cancer bone metastases can be found in about 70% and 60%, respectively. Metastatic disease to the bones is strong-... 

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